When the Navy needed to replace the aging F-14 Tomcat, the budget wasn't there for an all new aircraft. So, the F/A-18E/F Super Hornet was developed as a larger, more advanced derivative of the existing F/A-18 Hornet. The end result was an entirely new aircraft based on some existing designs. The F/A-18E/F is larger, has more powerful engines and can carry more weapons. By basing the Super Hornet on an existing design, the Navy found it easier to get Congressional approval. In the end, the Super Hornet came in on budget, on schedule and underweight. In the Iraq War, the F-18F was used in many ways, including close-in air support. It has a top speed of 1.8 mach. On board ship, the Navy flies both F-18Es and F-18Fs, which take the place of four different older aircraft.